Non-aqueous ink composition, recording method using the same, and method for producing a recorded material

Abstract

Provided is a nonaqueous ink composition which has fine record drying characteristics when being disposed on the surface of a substrate and from which a recorded matter having excellent post-processability is obtained.　The nonaqueous ink composition contains organic solvents. The organic solvents include an organic solvent (a) and an organic solvent (b).　Organic solvent (a): Glycol ether dialkyl. Organic solvent (b): At least one selected from the group consisting of alkylamide-based solvents (b1), cyclic amide-based solvents (b2), and lactone-based solvents (b3) each having a ring including six or more members.

Description

[Technical Field]

[0001] The present invention relates to a non-aqueous ink composition, a recording method using the same, and a method for producing a recorded material. [Background technology]

[0002] As ink compositions, aqueous ink compositions, in which a colorant is dissolved or dispersed in water or a mixture of water and an organic solvent, and non-aqueous ink compositions, in which a colorant is dissolved or dispersed in an organic solvent that does not contain water, are widely used.

[0003] For example, Patent Document 1 describes a non-aqueous ink composition containing a colorant, a predetermined glycol ether, and a five-membered ring lactone solvent. Patent Document 1 states that this non-aqueous ink composition is suitable for printing on substrates and has excellent print quality, recording stability, recording drying properties, and ink storage stability.

[0004] Furthermore, Patent Document 1 states that the non-aqueous ink composition preferably contains a binder resin, and that including a binder resin allows for adjustment of the viscosity of the non-aqueous ink composition and improvement of its fixability to polyvinyl chloride substrates. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] WO2004 / 007626 [Overview of the project] [Problems that the invention aims to solve]

[0006] Now, five-membered ring lactone solvents are solvents that easily penetrate resin substrates, and non-aqueous ink compositions containing five-membered ring lactone solvents have excellent recording and drying properties, but they also have high penetration into resin substrates.

[0007] However, the inventors have found that when a non-aqueous ink composition penetrates a resin substrate and the amount of penetration is large, the solvent in the non-aqueous ink composition remains in the substrate even after the non-aqueous ink composition on the surface of the resin substrate has been thoroughly dried. When the solvent in the non-aqueous ink composition remains in the substrate in this way, the solvent remaining in the substrate may evaporate after the film is laminated to the recording surface of the recording material, causing the film to lift. In this specification, this problem may be referred to as a decrease in the post-processability of the recording material.

[0008] The present invention aims to provide a non-aqueous ink composition that exhibits excellent recording drying properties and good post-processing properties for recorded materials.

[0009] Furthermore, examples of substrates (recording media) used in non-aqueous ink compositions include resin substrates having an adhesive layer on one side. In such cases, a non-aqueous ink composition may be recorded on the side of the resin substrate without the adhesive layer, and the side with the adhesive layer may be adhered to another object.

[0010] However, our research has revealed that in non-aqueous ink compositions containing a five-membered ring lactone solvent, the five-membered ring lactone solvent in the non-aqueous ink composition penetrates from the decorative layer to the adhesive layer on the back, resulting in a deterioration of the adhesion of the adhesive layer (adhesion between the recorded material and the substrate).

[0011] Furthermore, our research has revealed that when a recording on a resin substrate on which a non-aqueous ink composition is recorded is stretched, the decorative layer of the non-aqueous ink composition turns white, and it does not become a decorative layer with the desired color and pattern.

[0012] The present invention aims to provide a non-aqueous ink composition that can be used on various substrates, and that, even when recording (printing) the non-aqueous ink composition on the substrate surface on the side without the adhesive layer, such as when using a resin substrate having an adhesive layer on one side, the deterioration of the adhesive layer (adhesion between the recorded material and the substrate) is suppressed, and the whitening of the decorative layer is effectively suppressed even when the recorded material is stretched. [Means for solving the problem]

[0013] The inventors of the present invention conducted diligent research to solve the above problems and found that a non-aqueous ink composition containing a predetermined organic solvent can solve the above problems, thus completing the present invention.

[0014] Furthermore, the inventors diligently studied to solve the above problems and found that a non-aqueous ink composition containing a predetermined organic solvent and a resin having a predetermined weight-average absolute molecular weight can solve the above problems, thus completing the present invention. Specifically, the present invention provides the following.

[0015] (1) A non-aqueous ink composition containing an organic solvent, wherein the organic solvent is the following organic solvent (a) and the following organic solvent (b). Organic solvent (a): Glycol ether dialkyl Organic solvent (b): At least one selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with 6 or more membered rings (b3).

[0016] (2) The non-aqueous ink composition according to (1), wherein the content of the organic solvent (b) is in the range of 3.0% by mass or more and 30.0% by mass or less of the total amount of the non-aqueous ink composition.

[0017] (3) The non-aqueous ink composition according to (1) or (2), wherein the organic solvent (a) is a glycol ether dialkyl represented by the following formula (1). [ka] (In formula (1), R1 and R3 are alkyl groups, and R2 represents an ethylene group or a propylene group. n represents an integer from 2 to 4.)

[0018] (4) The non-aqueous ink composition according to (3), wherein the total number of carbon atoms contained in R1 and R3 in the formula (1) is 2 or more and 6 or less.

[0019] (5) The non-aqueous ink composition according to (4), wherein in the organic solvent (a), R1 in the formula (1) is a methyl group or an ethyl group, R3 in the formula (1) is an ethyl group, and / or R1 and R3 in the formula (1) are methyl groups and R2 is a propylene group.

[0020] (6) The non-aqueous ink composition according to any one of (1) to (5), wherein the content of impurities derived from the organic solvent (a) is 0.5% by mass or less in the total amount of the organic solvent (a), and the content of impurities derived from the organic solvent (b) is 0.5% by mass or less in the total amount of the organic solvent (b).

[0021] (7) A non-aqueous ink composition containing an organic solvent and a resin, wherein the organic solvent contains the following organic solvent (b), and the weight average absolute molecular weight of the resin is 15,000 or more and 80,000 or less. Organic solvent (b): at least one selected from the group consisting of an alkylamide-based solvent (b1), a cyclic amide-based solvent (b2), and a lactone-based solvent (b3) having 6 or more members

[0022] <​​​​​​​​(10) The non-aqueous ink composition according to any one of (1) to (9), wherein the organic solvent (b) is an alkylamide solvent (b1).

[0025] (11) The alkylamide solvent (b1) is the non-aqueous ink composition described in (10) which is represented by the following general formula (2). [ka] (In formula (2), R4 represents hydrogen or an alkyl group having 1 to 4 carbon atoms, and R5 represents an alkyl group having 2 to 4 carbon atoms.)

[0026] (12) The non-aqueous ink composition according to (11), wherein the alkylamide solvent (b1) contains at least one selected from the group consisting of N,N-diethylformamide, N,N-diethylpropanamide, and N,N-diethylacetamide.

[0027] (13) The non-aqueous ink composition according to any one of (1) to (9), wherein the organic solvent (b) is a cyclic amide solvent (b2).

[0028] (14) The cyclic amide solvent (b2) is the non-aqueous ink composition described in (13) which is represented by the following general formula (3). [ka] (In formula (3), R6 is an alkylene group having 4 to 5 carbon atoms, and R7 represents hydrogen, an alkyl group having 1 to 2 carbon atoms, or an unsaturated hydrocarbon group.)

[0029] (15) The non-aqueous ink composition according to (14), wherein the cyclic amide solvent (b2) contains at least one selected from the group consisting of ε-caprolactam, N-methylcaprolactam, and N-vinylcaprolactam.

[0030] (16) The non-aqueous ink composition according to any one of (1) to (9), wherein the organic solvent (b) is a lactone-based solvent (b3) with a 6-membered ring or more.

[0031] (17) The lactone-based solvent (b3) having six or more membered rings is the non-aqueous ink composition described in (16) and represented by the following general formula (4). [ka] (In formula (4), R8 is an alkylene group having 4 to 5 carbon atoms, and R9 represents hydrogen or an alkyl group having 1 to 2 carbon atoms.)

[0032] (18) The non-aqueous ink composition according to (17), wherein the lactone-based solvent (b3) having six or more membered rings contains at least one selected from the group consisting of δ-valerolactone, δ-hexanolactone, and ε-caprolactone.

[0033] (19) The water content is 1.0% by mass or less of the total amount of the non-aqueous ink composition. A non-aqueous ink composition according to any one of (1) to (18).

[0034] (20) Used in resin substrates A non-aqueous ink composition according to any one of (1) to (19).

[0035] (21) Dispense a non-aqueous ink composition described in any of (1) to (19) onto the surface of a substrate using an inkjet method. Recording method.

[0036] (22) Dispense a non-aqueous ink composition described in any of (1) to (19) onto the surface of a substrate using an inkjet method. Method for manufacturing records. [Effects of the Invention]

[0037] The non-aqueous ink composition of the present invention exhibits excellent recording and drying properties, and good post-processing capabilities for recorded materials. For this reason, the non-aqueous ink composition of the present invention can be used on various substrates (recording media), including non-absorbent substrates such as resin substrates and metal plate glass, absorbent substrates such as paper and cloth, and substrates with surface coatings.

[0038] Furthermore, the non-aqueous ink composition of the present invention can be used on various substrates (recording media), including non-absorbent substrates such as resin substrates and metallic glass plates, absorbent substrates such as paper and cloth, and substrates with surface coatings. For example, even when using a resin substrate with an adhesive layer on one side and recording (printing) the non-aqueous ink composition of the present invention on the substrate surface without the adhesive layer, it is possible to suppress deterioration of the adhesiveness of the adhesive layer (adhesion between the recorded material and the substrate) and to effectively suppress whitening of the decorative layer even when the recorded material is stretched. [Modes for carrying out the invention]

[0039] The following describes specific embodiments of the present invention in detail. However, the present invention is not limited in any way to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention.

[0040] <Non-aqueous ink composition of the first embodiment> The non-aqueous ink composition according to this embodiment is a non-aqueous ink composition containing an organic solvent, characterized in that it contains a glycol ether dialkyl (organic solvent (a)) and at least one selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with a ring of 6 or more members (b3) as the organic solvent (organic solvent (b)).

[0041] Such a non-aqueous ink composition exhibits excellent recording and drying properties, and good post-processing capabilities for recorded materials. Therefore, the non-aqueous ink composition according to this embodiment can be used on various substrates (recording media) including resin substrates.

[0042] Here, "non-aqueous ink composition" means an ink composition (oil-based ink composition) that contains an organic solvent but intentionally does not contain water, excluding water that is inevitably present due to moisture in the atmosphere or additives, and is different from an aqueous ink composition in which a colorant is dissolved or dispersed in water or a mixture of water and an organic solvent. Being a "non-aqueous ink composition" allows for fast drying and facilitates printing (recording) on ​​non-absorbent substrates such as resin substrates and metal substrates. The same applies to the non-aqueous ink composition of the second embodiment described later.

[0043] The water content is preferably 5.0% by mass or less of the total amount of the non-aqueous ink composition, more preferably 3.0% by mass or less, even more preferably 1.0% by mass or less, and still more preferably 0.5% by mass or less. For example, when the non-aqueous ink composition is a non-aqueous inkjet ink composition that is ejected onto the surface of a substrate using an inkjet method, problems such as clogging of the ink composition in the nozzle are eliminated, and ejection stability, storage stability, etc., can be improved.

[0044] The following describes each component included in the non-aqueous ink composition according to this embodiment.

[0045] [Organic solvents] The organic solvent contains organic solvent (a) and organic solvent (b).

[0046] Organic solvent (a): Glycol ether dialkyl Organic solvent (b): At least one selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with 6 or more membered rings (b3).

[0047] The following provides a more detailed explanation of organic solvent (a) and organic solvent (b).

[0048] (Organic solvent (a)) The organic solvent (a) is a glycol ether dialkyl. A glycol ether dialkyl is a compound in which the OH groups at both ends of a glycol are substituted with alkyl groups. Because glycol ether dialkyl has moderate volatility, the non-aqueous ink composition dries before blurring occurs in the image, resulting in good image quality. Furthermore, because glycol ether dialkyl does not penetrate resins well, it can improve the post-processing properties of the recorded material. In addition, because glycol ether dialkyl does not dissolve or swell much in plastic materials and adhesives, if the non-aqueous ink composition is a non-aqueous inkjet ink composition that is ejected onto the surface of a substrate using an inkjet method, it also has good compatibility with inkjet heads and other components.

[0049] Examples of glycol ether dialkyls include glycol ether dialkyls represented by the following formula (1).

[0050] [ka] (In formula (1), R1 and R3 are alkyl groups, and R2 represents an ethylene group or a propylene group. n represents an integer between 2 and 4.)

[0051] Specifically, glycol ether dialkyls include ethylene glycol dibutyl ether, ethylene glycol dipropyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dipropyl ether, diethylene glycol propyl methyl ether, diethylene glycol isopropyl methyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, diethylene glycol butyl ethyl ether, diethylene glycol methyl-2-ethylhexyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol ethyl methyl ether, and tetraethylene glycol dimethyl ether. Examples include tetraethylene glycol diethyl ether, tetraethylene glycol ethyl methyl ether, propylene glycol diethyl ether, propylene glycol ethyl methyl ether, propylene glycol methyl propyl ether, propylene glycol methyl butyl ether, propylene glycol methyl-2-ethylhexyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol ethyl methyl ether, dipropylene glycol methyl propyl ether, dipropylene glycol dipropyl ether, dipropylene glycol methyl butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, and tripropylene glycol ethyl methyl ether.

[0052] Among glycol ether dialkyls, glycol ether dialkyls in which the total number of carbon atoms in R1 and R3 in formula (1) is 2 or more and 8 or less are preferred, glycol ether dialkyls in which the total number of carbon atoms in R1 and R3 in formula (1) is 2 or more and 6 or less are more preferred, glycol ether dialkyls in which R1 in formula (1) is a methyl group or an ethyl group and R3 is an ethyl group, and / or glycol ether dialkyls in which R1 and R3 in formula (1) are methyl groups and R2 is a propylene group are even more preferred.

[0053] Glycol ether dialkyls in which the total number of carbon atoms in R1 and R3 is between 2 and 6 have higher volatility compared to, for example, diethylene glycol dibutyl ether (where the total number of carbon atoms in R1 and R3 is 8), resulting in a non-aqueous ink composition with excellent recording drying properties.

[0054] Examples of glycol ether dialkyls in which the total number of carbon atoms in R1 and R3 is between 2 and 6 include diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol isopropyl methyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and tetraethylene glycol diethyl ether.

[0055] Furthermore, glycol ether dialkyls in formula (1) where R1 is a methyl or ethyl group and R3 is an ethyl group, and / or glycol ether dialkyls in formula (1) where R1 and R3 are methyl groups and R2 is a propylene group, have even lower permeability compared to, for example, diethylene glycol dimethyl ether (where R1 and R3 are methyl groups and R2 is an ethylene group). Therefore, the post-processability of the recorded material can be improved even more effectively.

[0056] Examples of glycol ether dialkyls in formula (1) where R1 is a methyl or ethyl group and R3 is an ethyl group include diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, and tetraethylene glycol diethyl ether. An example of a glycol ether dialkyl in formula (1) where R1 and R3 are methyl groups and R2 is a propylene group is dipropylene glycol dimethyl ether.

[0057] The lower limit of the content of organic solvent (a) is not particularly limited, but it is preferably 30.0% by mass or more, more preferably 40.0% by mass or more, and even more preferably 50.0% by mass or more, in the total amount of the non-aqueous ink composition.

[0058] There is no particular upper limit to the content of organic solvent (a), but it is preferable that it be contained in 90.0% by mass or less of the total amount of the non-aqueous ink composition, and more preferably 80.0% by mass or less.

[0059] Furthermore, since glycol ether dialkyl can absorb water vapor, for example, from the atmosphere, it is preferable to dry the glycol ether dialkyl beforehand before mixing it with other components. By using pre-dried glycol ether dialkyl, the water content in the non-aqueous ink composition can be adjusted to an appropriate amount (for example, 1.0% by mass or less of the total amount of the non-aqueous ink composition). Methods for drying glycol ether dialkyl include, for example, blowing an inert gas (e.g., nitrogen gas) that has been dried under an inert gas atmosphere such as nitrogen for a predetermined time.

[0060] Furthermore, organic solvent (a) (glycol ether dialkyl) is prone to generating impurities such as polymers, by-reaction products, and decomposition products during the manufacturing process. For example, commercially available glycol ether dialkyl may contain impurities of about 10% by mass of the total amount of glycol ether dialkyl. Therefore, it is preferable to pre-mix organic solvent (a) with other components so that the content of impurities derived from organic solvent (a) is 0.5% by mass or less of the total amount of organic solvent (a). Low-boiling point impurities in organic solvent (a) can worsen the post-processing properties of the recorded material, and may cause problems such as dissolution or swelling in plastics and adhesives used in printer components such as inkjet heads. Also, if the impurities contained in glycol ether dialkyl have high boiling points, the recording drying properties of the non-aqueous ink composition may decrease, causing printing to bleed. By pre-mixing organic solvent (a) with other components so that the content of impurities derived from organic solvent (a) is 0.5% by mass or less of the total amount of organic solvent (a), the recording drying properties, material compatibility, and post-processing properties of the recorded material are further improved.

[0061] Examples of impurities contained in the organic solvent (a) include, but are not limited to, triethylene glycol (boiling point 285°C), tetraethylene glycol (boiling point 327°C), polyethylene glycol (boiling point 330°C or higher), ethylene glycol monoethyl ether (boiling point 135°C), ethylene glycol monomethyl ether (boiling point 124°C), ethylene glycol diethyl ether (boiling point 121°C), ethylene glycol dimethyl ether (boiling point 98°C), diethyl ether (boiling point 35°C), ethyl methyl ether (boiling point 12°C), diethyl ketone (boiling point 101°C), dimethyl ketone (boiling point 57°C), ethyl methyl ketone (boiling point 80°C), ethoxyethanol (boiling point 135°C), ethanol (boiling point 78°C), etc.

[0062] Methods for purifying organic solvent (a) include repeatedly distilling organic solvent (a), reducing the temperature increment of the distillation to minimize the inclusion of impurities, and repeatedly extracting the solvent. Furthermore, in industrial manufacturing processes, this can be achieved by adding measures to suppress contamination in addition to the above-mentioned processes.

[0063] (Organic solvent (b)) The organic solvent (b) is at least one selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with six or more membered rings (b3). This organic solvent (b) has lower penetration into the substrate compared to non-aqueous ink compositions containing five-membered lactone solvents. Therefore, it results in a non-aqueous ink composition with good post-processing properties for recorded materials.

[0064] Furthermore, this organic solvent (b) is a solvent that penetrates the substrate to some extent and dries quickly on the substrate surface. For this reason, ink compositions containing organic solvent (b) have high recording-drying properties, similar to non-aqueous ink compositions containing five-membered ring lactone solvents, and produce clear prints with less bleeding during printing (recording). This effect of reduced printing bleeding cannot be achieved simply by selecting a solvent with a low boiling point to improve drying properties.

[0065] Furthermore, since this organic solvent (b) does not dissolve or swell plastic components or adhesives, if the non-aqueous ink composition is a non-aqueous inkjet ink composition that is ejected onto the surface of a substrate using an inkjet method, it will also have good compatibility with inkjet heads and other components.

[0066] The alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with six or more membered rings (b3) contained in organic solvent (b) will be explained below.

[0067] (1) Alkylamide solvents Alkylamide solvents are solvents containing alkyl groups (Cn H 2n+1 A solvent comprising a compound having a -) and a -C(=O)-N- group (amide bond), and composed of a compound consisting of hydrogen or an alkyl group and a -C(=O)-N- group. For example, alkylamide solvents having the following structures can be preferably used.

[0068] [ka] (In formula (2), R4 represents hydrogen or an alkyl group having 1 to 4 carbon atoms, and R5 represents an alkyl group having 2 to 4 carbon atoms.)

[0069] Examples of alkylamide solvents include N,N-diethylformamide, N,N-diethylacetamide, N,N-dipropylformamide, N,N-dibutylformamide, N,N-diethylpropanamide, and N,N-dipropylpropanamide. Among these, from the viewpoint of particularly achieving the effects of the present invention, it is preferable to contain at least one selected from the group consisting of N,N-diethylformamide, N,N-diethylpropanamide, and N,N-diethylacetamide.

[0070] While N,N-dimethylformamide and N,N-dimethylacetamide may be included, it is preferable that they are not included in order to particularly achieve the effects of the present invention.

[0071] (2) Cyclic amide solvents A cyclic amide solvent is a solvent having a cyclic structure, and that cyclic structure contains a -C(=O)-N- group. For example, cyclic amide solvents having the following structures are preferably used.

[0072] [ka] (In formula (3), R6 is an alkylene group having 4 to 5 carbon atoms, and R7 represents hydrogen, an alkyl group having 1 to 2 carbon atoms, or an unsaturated hydrocarbon group.)

[0073] Furthermore, R7 is more preferably hydrogen or an alkyl group having 1 to 2 carbon atoms.

[0074] Examples of cyclic amide solvents include N-methylcaprolactam, N-acetylcaprolactam, ε-caprolactam, N-vinylcaprolactam, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-ethyl-ε-caprolactam, N-propyl-ε-caprolactam, and N-methyl-ε-caprolactam. Among these, it is preferable to contain at least one selected from the group consisting of ε-caprolactam, N-methylcaprolactam, and N-vinylcaprolactam.

[0075] N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and N-methyloxazolidinone may be included, but it is preferable that they are not included in order to particularly achieve the effects of the present invention.

[0076] (3) Lactone-based solvents with 6 or more member rings A lactone-based solvent with six or more membered rings is a solvent having a cyclic ester structure with six or more membered rings. For example, lactone-based solvents having the following structures can be preferably used.

[0077] [ka] (In formula (4), R8 is an alkylene group having 4 to 5 carbon atoms, and R9 represents hydrogen or an alkyl group having 1 to 2 carbon atoms.)

[0078] Examples of lactone-based solvents with six or more membered rings include δ-valerolactone, δ-hexanolactone, δ-heptalactone, δ-octaractone, δ-nonalactone, δ-decalactone, δ-undecalactone, and ε-caprolactone.

[0079] A non-aqueous ink composition that contains the above-mentioned organic solvent (a) and an organic solvent (b) selected from the group consisting of alkylamide solvent (b1), cyclic amide solvent (b2), and lactone solvent (b3) with 6 or more membered rings will exhibit the effects of the present invention. Among these, it is preferable that the organic solvent (b) contains at least one of alkylamide solvent (b1) and cyclic amide solvent (b2), and it is particularly preferable that the organic solvent (b) contains alkylamide solvent (b1).

[0080] The upper limit of the content of organic solvent (b) (at least one selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with 6 or more membered rings (b3)) is not particularly limited, but it is preferably 60.0% by mass or less, more preferably 45.0% by mass or less, even more preferably 35.0% by mass or less, and still more preferably 17.0% by mass or less of the total amount of the non-aqueous ink composition.

[0081] The lower limit of the content of organic solvent (b) is not particularly limited, but it is preferably 3.0% by mass or more, and more preferably 5.0% by mass or more, in the total amount of the ink composition.

[0082] The upper and lower limits for the content of the organic solvent (b) described above are common to all alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with six or more membered rings (b3). In particular, when the organic solvent (b) is a lactone solvent with six or more membered rings (b3), it is most preferable that it be contained in an amount of 5.0% by mass or more and 15.0% by mass or less of the total amount of the non-aqueous ink composition.

[0083] It is preferable to pre-mix the organic solvent (b) (at least one selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with 6 or more membered rings (b3)) with other components so that the content of impurities derived from the organic solvent (b) is 0.5% by mass or less of the total amount of organic solvent (b). Low-boiling point impurities contained in the organic solvent (b) may cause deterioration of the post-processing properties of the recorded material, or cause problems such as dissolution or swelling of plastics and adhesives used in printer components such as inkjet heads. By pre-mixing the organic solvent (b) with other components so that the content of impurities derived from the organic solvent (b) is 0.5% by mass or less of the total amount of organic solvent (b), the recording drying properties, component suitability, and post-processing properties of the recorded material are further improved. Furthermore, it is possible to more effectively suppress printing blurring caused by reduced recording drying properties due to high-boiling point impurities contained in the organic solvent (b).

[0084] Methods for purifying organic solvent (b) include repeatedly distilling organic solvent (b), reducing the temperature increment of the distillation to minimize the inclusion of impurities, and repeatedly extracting the solvent. Furthermore, in industrial manufacturing processes, this can be achieved by adding measures to suppress contamination in addition to the above-mentioned processes.

[0085] (Other organic solvents) The organic solvent may contain organic solvents other than the organic solvents (a) and (b) described above. Specifically, examples include glycol ether monoalkyls and carbonate esters in which one of the OH groups of the glycol is alkyl-substituted.

[0086] Examples of glycol ether monoalkyls include ethylene glycol mono-n-butyl ether, ethylene glycol mono-isobutyl ether, ethylene glycol mono-t-butyl ether, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl ether), triethylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl) ether, tetraethylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl) Examples include sil) ether, propylene glycol mono-n-butyl ether, propylene glycol mono-isobutyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-2-ethylhexyl ether, dipropylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl) ether, tripropylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl) ether, tetrapropylene glycol monomethyl ether (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl), etc.

[0087] Examples of carbonate esters include ethylene carbonate and propylene carbonate.

[0088] Furthermore, it may contain organic solvents other than those listed above. Specifically, cyclic esters such as γ-butyrolactone, γ-valerolactone, γ-hexalactone, γ-heptalactone, γ-octaractone, γ-nonalactone, γ-decalactone, and γ-undecalactone; oxazolidinone solvents such as 3-methyl-2-oxazolidinone, 3-ethyl-2-oxazolidinone, and N-vinylmethyloxazolidinone; triethylene glycol butyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol butyl ether acetate, propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, 1-methoxy-2-propyl acetate, 2-methylbutyl acetate, 3-methoxybutyl ether acetate, and cyclohexyl butyl ether acetate. Acetate solvents such as ammonium acetate; amide solvents different from alkylamide solvents (b1) and cyclic amide solvents (b2), such as 3-methoxypropanamide, 3-butoxypropanamide, N,N-dimethyl-3-methoxypropanamide, N,N-dibutyl-3-methoxypropanamide, N,N-dibutyl-3-butoxypropanamide, and N,N-dimethyl-3-butoxypropanamide; alkyl alcohols with 1 to 5 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, and n-pentanol; monohydric alcohol solvents such as 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-propanol, 1-methoxy-2-propanol, and 3-methoxy-n-butanol;Ketones or ketos such as acetone, diacetone alcohol, methyl ethyl ketone, methyl-n-propyl ketone, methyl isopropyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, methyl-n-amyl ketone, methylhexyl ketone, methyl isoamyl ketone, diethyl ketone, ethyl-n-propyl ketone, ethyl isopropyl ketone, ethyl-n-butyl ketone, ethyl isobutyl ketone, di-n-propyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, isophorone, acetyl ketone, etc. Glycols; ethers such as tetrahydrofuran and dioxane; oxyethylene or oxypropylene copolymers such as polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-propanediol, isobutylene glycol, triethylene glycol, tripropylene glycol, tetraethylene glycol, 1,3-propanediol, 2-methyl-1,2-propanediol, 2-methyl-1,2-propanediol, 1,2-butanediol, 1,3 Diols such as -butanediol, 1,4-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-butanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol; triols such as glycerin, trimethylolethane, trimethylolpropane, 1,2,6-hexanetriol; tetrahydric alcohols such as mesoerythritol and pentaerythritol; monoethanolamine Alkanolamines such as diethanolamine, triethanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, and N-butyldiethanolamine; Acetate esters such as methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, hexyl acetate, and octyl acetate; Lactic acid esters such as methyl lactate, ethyl lactate, butyl lactate, propyl lactate, ethylhexyl lactate, amyl lactate, and isoamyl lactate;Examples include saturated hydrocarbons such as n-hexane, isohexane, n-nonane, isononane, dodecane, and isododecane; unsaturated hydrocarbons such as 1-hexene, 1-heptene, and 1-octene; cyclic unsaturated hydrocarbons such as cyclohexene, cycloheptene, cyclooctene, 1,1,3,5,7-cyclooctatetraene, and cyclododecene; aromatic hydrocarbons such as benzene, toluene, and xylene; morpholins such as N-methylmorpholine, N-ethylmorpholine, and N-formylmorpholine; terpene solvents; and dibasic acid esters such as dimethyl oxalate, diethyl oxalate, dimethyl malonate, diethyl malonate, dipropyl malonate, dimethyl succinate, diethyl succinate, dimethyl glutarate, and diethyl glutarate. It is preferable to select a solvent with an appropriate HLB value depending on the resin and dispersant being combined.

[0089] Furthermore, a five-membered ring lactone solvent may be contained, but it is preferable that it is not contained. If a five-membered ring lactone solvent is contained, the content of the five-membered ring lactone solvent is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 1.0% by mass or less, and still more preferably not contained at all.

[0090] Examples of five-membered ring lactone solvents include γ-butyrolactone, γ-valerolactone, γ-hexanolactone, and γ-heptanolactone.

[0091] [Colorants] The colorant contained in the non-aqueous ink composition according to this embodiment is not particularly limited and may be dye-based or pigment-based, but it is preferable to use a pigment (pigment-based colorant) from the viewpoint of good water resistance, light resistance, and other resistances of the recorded material. The pigments that can be used in the non-aqueous ink composition according to this embodiment are not particularly limited and include organic pigments or inorganic pigments used in conventional ink compositions. These may be used individually or in combination of two or more.

[0092] Specific examples of organic pigments include, for instance, insoluble azo pigments, soluble azo pigments, derivatives from dyes, phthalocyanine organic pigments, quinacridone organic pigments, perylene organic pigments, perinone organic pigments, azomethine organic pigments, anthraquinone organic pigments (anthrone organic pigments), xanthene organic pigments, diketopyrrolopyrrole organic pigments, dioxazine organic pigments, nickel azo pigments, isoindolinone organic pigments, pyranthrone organic pigments, thioindigo organic pigments, condensed azo organic pigments, benzimidazolon organic pigments, quinophthalone organic pigments, isoindoline organic pigments, quinacridone solid solution pigments, perylene solid solution pigments and other organic solid solution pigments, as well as other pigments such as lake pigments and carbon black.

[0093] Examples of organic pigments using Color Index (CI) numbers include: CI Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 20, 24, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 117, 120, 125, 128, 129, 130, 137, 138, 139, 147, 148, 150, 151, 153, 154, 155, 166, 168, 180, 185, 213, 214; CI Pigment Red 5, 7, 9, 12, 48, 49, 52, 53, 57:1, 97, 112, 122, 123, 146, 149, 150, 168, 177, 180, 184 Examples include 192, 202, 206, 208, 209, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, 254, 255, 269, 291, CI Pigment Orange 16, 36, 43, 51, 55, 59, 61, 64, 71, 73, CI Pigment Violet 19, 23, 29, 30, 37, 40, 50, CI Pigment Blue 15, 15:1, 15:3, 15:4, 15:6, 16, 22, 60, 64, CI Pigment Green 7, 36, 58, 59, 62, 63, CI Pigment Brown 23, 25, 26, CI Pigment Black 7, etc.

[0094] Specific examples of dyes that can be used in the non-aqueous ink composition according to this embodiment include azo dyes, benzoquinone dyes, naphthoquinone dyes, anthraquinone dyes, cyanine dyes, squarylium dyes, croconium dyes, merocyanine dyes, stilbene dyes, diarylmethane dyes, triarylmethane dyes, fluorane dyes, spiropyran dyes, phthalocyanine dyes, indigo dyes such as indigoids, fulgide dyes, nickel complex dyes, and azulene dyes.

[0095] Specific examples of inorganic pigments that can be used in the non-aqueous ink composition according to this embodiment include titanium dioxide, barium sulfate, calcium carbonate, zinc oxide, barium carbonate, silica, talc, clay, synthetic mica, alumina, zinc oxide, lead sulfate, lead yellow, zinc yellow, red iron(III) oxide, cadmium red, ultramarine, Prussian blue, chromium oxide green, cobalt green, amber, titanium black, aluminum, titanium, indium, synthetic iron black, inorganic solid solution pigments, and the like.

[0096] In the non-aqueous ink composition according to this embodiment, the average dispersed particle size of the pigment that can be contained is not particularly limited, as long as it enables the desired color development. Although it varies depending on the type of pigment used, it is preferable that the volume average particle size be in the range of 5 nm or more, more preferably 20 nm or more, and even more preferably 30 nm or more, from the viewpoint of good dispersibility and dispersion stability of the pigment and obtaining sufficient coloring power. The lightfastness of the non-aqueous ink composition can be improved by having the volume average particle size be above the lower limit of the above value. It is preferable that the volume average particle size be in the range of 300 nm or less, more preferably 200 nm or less, and even more preferably 150 nm or less. The ejection stability of the inkjet can be improved when the volume average particle size is below the upper limit of the above value, in the case that the non-aqueous ink composition is a non-aqueous inkjet ink composition that is ejected onto the surface of a substrate by an inkjet method. In this embodiment, the volume average particle size of the pigment is the volume average particle size (D50) measured under conditions of 25°C using a particle size distribution analyzer (NANOTRACWAVE particle size analyzer manufactured by Microtrac Bell Co., Ltd.).

[0097] Furthermore, in the case of an ink set containing the non-aqueous ink composition according to this embodiment, the volume-average particle sizes of the pigments contained in each non-aqueous ink composition may be the same or different.

[0098] In the non-aqueous ink composition according to this embodiment, the pigment content is not particularly limited as long as it is possible to form the desired image, and can be adjusted as appropriate. Specifically, although it varies depending on the type of pigment, it is preferably 0.05% by mass or more, and more preferably 0.1% by mass or more, of the total amount of the non-aqueous ink composition. It is preferably 20% by mass or less, and more preferably 10% by mass or less, of the total amount of the non-aqueous ink composition. By having a pigment content within the range of 0.05% by mass or more, or 20% by mass or less, it is possible to achieve an excellent balance between the dispersion stability of the pigment and the coloring power.

[0099] Furthermore, the non-aqueous ink composition according to this embodiment is not particularly limited in the color to be recorded (printed), and colorants may be selected and combined according to the desired color for the purpose. The colors can be various inks such as yellow, magenta, cyan, and black, as well as light magenta, light cyan, light black, orange, green, red, and white.

[0100] [resin] The non-aqueous ink composition according to this embodiment may contain a resin for the purpose of improving the fixation, water resistance, and stretchability of the decorative layer formed by the non-aqueous ink composition. The resin is not particularly limited, and for example, acrylic resins, polystyrene resins, polyester resins, vinyl chloride resins, vinyl acetate resins, vinyl chloride vinyl acetate copolymer resins, polyethylene resins, polyurethane resins, rosin-modified resins, phenolic resins, terpene resins, polyamide resins, vinyltoluene-α-methylstyrene copolymers, ethylene-vinyl acetate copolymers, cellulose acetate butyrate, cellulose acetate propionate, silicone resins, acrylamide resins, epoxy resins, or copolymers or mixtures thereof can be used. Among these, those containing acrylic resins, vinyl chloride resins, cellulose resins, polyester resins, and polyurethane resins are preferred. Alternatively, copolymers or mixtures thereof can be used.

[0101] In the non-aqueous ink composition according to this embodiment, it is preferable that it contains at least one acrylic resin and a copolymer resin of vinyl chloride and vinyl acetate (vinyl acetate), in order to improve water resistance, solvent resistance, and stretchability. Furthermore, if the non-aqueous ink composition contains one or more acrylic resin and a copolymer resin of vinyl chloride and vinyl acetate (vinyl acetate), it is possible to improve the ejection response and ejection stability during high-speed recording when the non-aqueous inkjet ink composition is ejected onto the surface of a substrate using an inkjet method.

[0102] The acrylic resin is not particularly limited as long as it is included as a main component of the monomer constituting the (meth)acrylic acid ester monomer. It may be a homopolymer of one type of radical polymerizable monomer, or a copolymer using two or more types of radical polymerizable monomers. In particular, preferred acrylic resins for the non-aqueous ink composition according to this embodiment are a polymer of methyl methacrylate alone, or a copolymer of methyl methacrylate and at least one compound selected from the group consisting of butyl methacrylate, ethoxyethyl methacrylate, and benzyl methacrylate. Examples of commercially available (meth)acrylic resins include "Paraloid B99N," "Paraloid B60," "Paraloid B66," and "Paraloid B82" from Rohm & Haas.

[0103] The vinyl chloride resin may be either a homopolymer composed of vinyl chloride monomers or a copolymer using two or more polymerizable monomers selected from each other. An example of a vinyl chloride polymer is a vinyl chloride-vinyl acetate copolymer resin. A vinyl chloride-vinyl acetate copolymer resin is a polymer of vinyl chloride monomer and vinyl acetate monomer. Examples of vinyl chloride-vinyl acetate copolymer resins include vinyl chloride-vinyl acetate copolymer, vinyl chloride / vinyl acetate / maleic acid copolymer, vinyl chloride / vinyl acetate / vinyl alcohol copolymer, vinyl chloride / vinyl acetate / hydroxyalkyl acrylate copolymer, and mixtures thereof. The above vinyl chloride-vinyl acetate copolymer resins can be obtained and used from Nisshin Chemical Industry Co., Ltd. under trade names such as "Solvine C," "Solvine CL," "Solvine CNL," "Solvine CLL," "Solvine CLL2," "Solvine C5R," "Solvine TA2," "Solvine TA3," "Solvine A," "Solvine AL," "Solvine TA5R," and "Solvine M5."

[0104] Cellulosic resins are resins having a cellulose skeleton obtained by introducing functional groups biologically or chemically from cellulose as a raw material. Examples of celluloseosic resins include cellulose acetate alkylate resins such as cellulose acetate butyrate resin, cellulose acetate propionate resin, and cellulose acetate propionate butyrate resin, as well as cellulose acetate resins, nitrocellulose resins, and mixtures thereof. The above cellulose resins can be obtained and used under product names such as "CAB551-0.01", "CAB551-0.2", "CAB553-0.4", "CAB531-1", "CAB381-0.1", "CAB381-0.5", "CAB381-2", "CAB381-20", "CAP504", and "CAP482-0.5" from EASTMAN.

[0105] Polyester resins are those that contain at least one structural unit obtained by polycondensation of an alcohol component and a carboxylic acid component. Polyester resins may also contain modified polyester resins. Polyester resins can be obtained and used under product names such as "VYLON226", "VYLON270", "VYLON560", "VYLON600", "VYLON630", "VYLON660", "VYLON885", "VYLONGK250", "VYLONGK810", and "VYLON GK890" from Toyobo Co., Ltd., and "elitleUE-3200", "elitleUE-3285", "elitleUE-3320", "elitleUE-9800", and "elitleUE-9885" from Unitika Corporation.

[0106] Polyurethane resins are those that contain at least one structural unit obtained by copolymerizing an alcohol component and an isocyanate component. Polyurethane resins may also include polyurethane resins modified with polyester, polyether, or caprolactone. The above polyurethane resins can be obtained and used under product names such as "Uriano KL-424," "Uriano KL-564," "Uriano KL-593," and "Uriano 3262" from Arakawa Chemical Industries, Ltd., and "Pandex 372E," "Pandex 390E," "Pandex 394E," "Pandex 304," "Pandex 305E," "Pandex P-870," "Pandex P-910," "Pandex P-895," "Pandex 4030," and "Pandex 4110" from DIC Corporation.

[0107] Furthermore, while these acrylic resins, vinyl chloride resins, cellulose resins, polyester resins, and polyurethane resins may be used individually, it is preferable to use a mixture of two types, and more preferably a mixture of acrylic resin and vinyl chloride resin. By adjusting the content ratio of acrylic resin to vinyl chloride resin, it is possible to control the requirements for color development, drying properties, film properties, and printability required for non-aqueous ink compositions. When mixing acrylic resin and vinyl chloride resin, the mixing ratio is not particularly limited and can be changed as appropriate.

[0108] The mass percentage of resin contained in the total amount of the non-aqueous ink composition according to this embodiment is not particularly limited, but for example, it is preferably 0.05% by mass or more of the total amount of the non-aqueous ink composition, more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, and more preferably 1% by mass or more. The mass percentage of resin contained in the total amount of the non-aqueous ink composition is not particularly limited, but for example, it is preferably 20% by mass or less of the non-aqueous ink composition, and more preferably 15% by mass or less.

[0109] [Dispersant] In the non-aqueous ink composition included in the ink set according to this embodiment, a dispersant may be used as needed. Any dispersant used in non-aqueous ink compositions can be used as the dispersant. A polymeric dispersant is preferable as the dispersant. Such dispersants have a main chain made of polyester, polyacrylic, polyurethane, polyamine, polycaprolactone, etc., and side chains that have polar groups such as amino groups, carboxyl groups, sulfone groups, and hydroxyl groups. Examples of polyacrylic dispersants include Disperbyk-2000, 2001, 2008, 2009, 2010, 2020, 2020N, ​​2022, 2025, 2050, 2070, 2095, 2150, 2151, 2155, 2163, 2164, BYKJET-9130, 9131, 9132, 9133, 9151 (manufactured by Bic Chemie), EfkaPX4310, PX4320, PX4330, PA4401, 4402, PA4403, 4570, 7411, 7477, PX4700, PX4701 (manufactured by BASF), and TREPLUS. Products such as D-1200, D-1410, D-1420, MD-1000 (manufactured by Otsuka Chemical Co., Ltd.), Floren DOPA-15BHFS, 17HF, 22, G-700, 900, NC-500, and GW-1500 (manufactured by Kyoeisha Chemical Co., Ltd.) are used. Examples of polycaprolactone-based dispersants include Ajisper PB821, PB822, PB881 (manufactured by Ajinomoto Fine Techno Co., Ltd.), Hinoact KF-1000, T-6000, T-7000, T-8000, T-8000E, T-9050 (manufactured by Kawaken Fine Chemical Co., Ltd.), Solsperse 20000, 24000, 32000, 32500, 32550, 32600, 33000, 33500, 34000, 35200, 36000, 37500, 39000, 71000, 76400, 76500, 86000, 88000, J180, J200 (manufactured by Lubrizol), and TEGO. Dispers 652, 655, 685, 688, and 690 (manufactured by Evonik Japan) are used.Preferred dispersants include BYKJET-9130, 9131, 9132, 9133, 9151, EfkaPX4310, PX4320, PX4330, PX4700, PX4701, Solsperse20000, 24000, 32000, 33000, 33500, 34000, 35200, 39000, 71000, 76500, 86000, 88000, J180, J200, TEGO Dispers655, 685, 688, 690, etc. These can be used individually or in mixtures thereof.

[0110] [Dispersing agent] In the non-aqueous ink composition included in the ink set according to this embodiment, a dispersion aid may be used as needed. The dispersion aid is adsorbed onto the surface of the colorant (pigment), and its functional groups enhance the affinity of the organic solvent and dispersant in the non-aqueous ink composition, thereby improving dispersion stability. As the dispersion aid, known pigment derivatives having functional groups such as acidic groups, basic groups, and neutral groups in the organic pigment residues can be used.

[0111] [Surfactants] In the non-aqueous ink composition according to this embodiment, surfactants may be added for the purpose of suppressing the volatilization of the ink composition in equipment such as nozzles and tubes, preventing solidification, improving resolubility after solidification, and reducing surface tension to improve wettability with the recording medium (substrate). For example, nonionic polyoxyalkylene alkyl ethers such as nonionic P-208, P-210, P-213, E-202S, E-205S, E-215, K-204, K-220, S-207, S-215, A-10R, A-13P, NC-203, NC-207 (manufactured by Nippon Oil & Fats Co., Ltd.), Emulgen 106, 108, 707, 709, A-90, A-60 (manufactured by Kao Corporation), and Flow Ren G-70, D-90, TG-740W (manufactured by Kyoeisha Chemical Co., Ltd.), Poem J-0081HV (manufactured by Riken Vitamin Co., Ltd.), Adekatol NP-620, NP-650, NP-660, NP-675, NP-683, NP-686, Adekacol CS-141E, TS-230E (manufactured by Adeka Co., Ltd.), Solgen 30V, 40, TW-20, TW-80, Neugen CX-100 (No. As for fluorine-based surfactants, it is preferable to use fluorine-modified polymers, such as BYK-340 (manufactured by Bic Chemie Japan Co., Ltd.), as a specific example, as for silicone-based surfactants, it is preferable to use polyester-modified silicone or polyether-modified silicone, such as BYK-313, 315N, 322, 326, 331, 347, 348, BYK-UV3500, 3510, 3530, 3570 (all manufactured by Bic Chemie Japan Co., Ltd.), as a specific example, as for acetylene glycol-based surfactants, examples include Surfinol® 82, 104, 465, 485, TG (all manufactured by Air Products Japan Co., Ltd.), and Orfin® STG, E1010 (all manufactured by Nisshin Chemical Co., Ltd.).

[0112] The surfactant is not limited to those mentioned above; any anionic, cationic, amphoteric, or nonionic surfactant can be used, and it should be selected appropriately according to the purpose of addition.

[0113] [Other ingredients] The non-aqueous ink composition according to this embodiment may optionally contain known additives such as antioxidants, stabilizers such as ultraviolet absorbers, epoxidants, polycarboxylic acids, surface modifiers, leveling agents (acrylic or silicone-based, etc.), defoamers, pH adjusters, bactericides, preservatives, deodorants, charge adjusters, and wetting agents. Specific examples of antioxidants include hindered phenol antioxidants, amine antioxidants, phosphorus antioxidants, sulfur antioxidants, and hydrazine antioxidants. Specifically, BHA (2,3-butyl-4-oxyanisole) and BHT (2,6-di-t-butyl-p-cresol) are examples. Benzophenone compounds or benzotriazole compounds can be used as ultraviolet absorbers. Furthermore, specific examples of epoxidized compounds include epoxy glycerides, epoxy fatty acid monoesters, and epoxy hexahydrophthalates, with ADEKA O-130P and ADEKA O-180A (manufactured by ADEKA Corporation) being specific examples. Specific examples of polycarboxylic acids include citric acid and maleic acid.

[0114] [Base material] The substrate (recording medium) that can be used with the non-aqueous ink composition according to this embodiment is not particularly limited, and may be a resin substrate, a non-absorbent substrate such as a metal plate or glass, an absorbent substrate such as paper or cloth, or a substrate with a surface coating such as a substrate with a receiving layer, and various substrates can be used. Among these, since the non-aqueous ink composition according to this embodiment is a non-aqueous ink composition that does not contain water, a resin substrate is preferably used. As resins, polyvinyl chloride polymers, acrylic, PET, polycarbonate, PE, PP, etc. are used. In particular, a substrate (recording medium) whose surface is made of a hard or soft polyvinyl chloride polymer is preferred. Examples of a substrate (recording medium) whose surface is made of a polyvinyl chloride polymer include a polyvinyl chloride substrate (film or sheet).

[0115] Furthermore, the non-aqueous ink composition according to this embodiment exhibits excellent recording drying properties and good post-processing properties for recorded materials. For this reason, it is more preferable to use it in resin substrates (so-called resin substrates for lamination) that are intended to be laminated to the recording surface of the recorded material, and is particularly preferable to use it in polyvinyl chloride polymer substrates for lamination.

[0116] <Non-aqueous ink composition of the second embodiment> The non-aqueous ink composition according to this embodiment is a non-aqueous ink composition containing an organic solvent, characterized in that it contains at least one (organic solvent (b)) selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with 6 or more membered rings (b3), and a resin having a weight-average absolute molecular weight of 15,000 or more and 80,000 or less.

[0117] Such a non-aqueous ink composition can be used on various substrates. For example, even when using a resin substrate with an adhesive layer on one side and recording (printing) the non-aqueous ink composition of the present invention on the substrate surface without the adhesive layer, it is possible to suppress deterioration of the adhesiveness of the adhesive layer (adhesion between the recorded material and the substrate) and to effectively suppress whitening of the decorative layer even when the recorded material is stretched.

[0118] Furthermore, resins with a weight-average absolute molecular weight of 15,000 to 80,000 have a high weight-average absolute molecular weight and low solubility in organic solvents, making it difficult to dissolve them in non-aqueous ink compositions, and even if dissolved once, they tend to precipitate. For example, if the non-aqueous ink composition is a non-aqueous inkjet ink composition that is ejected onto the surface of a substrate using an inkjet method, resin precipitates may adhere to the inkjet nozzle, causing nozzle chipping or bending, which reduces ejection stability and prevents normal printing. The non-aqueous ink composition according to this embodiment contains at least one organic solvent (b) selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with 6 or more membered rings (b3), making it possible to dissolve resins with high weight-average absolute molecular weight and maintain ejection stability.

[0119] The water content is preferably 5.0% by mass or less of the total amount of the non-aqueous ink composition, more preferably 3.0% by mass or less, even more preferably 1.0% by mass or less, and still more preferably 0.5% by mass or less. In particular, the non-aqueous ink composition according to this embodiment contains a resin with a large weight-average absolute molecular weight that can reduce the discharge stability and storage stability of the non-aqueous ink composition, but it contains an organic solvent (b) described later, and furthermore, the water content is 5.0% by mass or less of the total amount of the non-aqueous ink composition, which makes it possible to maintain discharge stability and storage stability.

[0120] The following describes each component included in the non-aqueous ink composition according to this embodiment.

[0121] [Organic solvents] The organic solvent contains organic solvent (b).

[0122] Organic solvent (b): At least one selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with 6 or more membered rings (b3). The following provides a more detailed explanation of organic solvent (b) and other organic solvents included in organic solvents.

[0123] (Organic solvent (b)) The organic solvent (b) is at least one selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with six or more membered rings (b3). This organic solvent (b) has lower penetration into the substrate compared to non-aqueous ink compositions containing five-membered lactone solvents. Therefore, it is possible to effectively suppress the deterioration of the adhesiveness of the adhesive layer (adhesion between the recorded material and the substrate) caused by the non-aqueous ink composition penetrating from the resin substrate to the adhesive layer.

[0124] Furthermore, this organic solvent (b) is a solvent that penetrates the substrate to some extent and dries quickly on the substrate surface. For this reason, ink compositions containing organic solvent (b) have high recording-drying properties, similar to non-aqueous ink compositions containing five-membered ring lactone solvents, and produce clear prints with less bleeding during printing (recording). This effect of reduced printing bleeding cannot be achieved simply by selecting a solvent with a low boiling point to improve drying properties.

[0125] Furthermore, by including at least one organic solvent (b) selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with six or more membered rings (b3), it becomes possible to effectively dissolve high molecular weight resins in non-aqueous ink compositions.

[0126] The alkylamide solvent (b1), cyclic amide solvent (b2), and lactone solvent with six or more membered rings (b3) are the same as the organic solvent (b) contained in the non-aqueous ink composition of the first embodiment described above. The preferred alkylamide solvent (b1), cyclic amide solvent (b2), and lactone solvent with six or more membered rings (b3) are also the same as the organic solvent (b) contained in the non-aqueous ink composition of the first embodiment described above.

[0127] A non-aqueous ink composition that contains at least one selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with six or more membered rings (b3) as the organic solvent (b) described above will exhibit the effects of the present invention. Among these, from the viewpoint of particularly exhibiting the effects of the present invention, it is preferable to contain at least one of alkylamide solvents (b1) and cyclic amide solvents (b2) as the organic solvent (b), and it is particularly preferable to contain alkylamide solvents (b1) as the organic solvent (b).

[0128] The upper limit of the content of organic solvent (b) (at least one selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with 6 or more membered rings (b3)) is not particularly limited, but it is preferably 30.0% by mass or less, more preferably 25.0% by mass or less, even more preferably 20.0% by mass or less, and still more preferably 15.0% by mass or less in the total amount of the non-aqueous ink composition.

[0129] The lower limit of the content of organic solvent (b) (at least one selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with 6 or more membered rings (b3)) is not particularly limited, but it is preferably 3.0% by mass or more, and more preferably 5.0% by mass or more, in the total amount of the ink composition.

[0130] The upper and lower limits for the content of the organic solvent (b) described above are common to all alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with six or more membered rings (b3). In particular, when the organic solvent (b) is a lactone solvent with six or more membered rings (b3), it is most preferable that it be contained in an amount of 5.0% by mass or more and 15.0% by mass or less of the total amount of the non-aqueous ink composition.

[0131] Furthermore, it is preferable to pre-mix the organic solvent (b) (at least one selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with 6 or more membered rings (b3)) with other components so that the content of impurities derived from the organic solvent (b) is 0.5% by mass or less of the total amount of organic solvent (b). For example, when a non-aqueous ink composition is recorded on a resin substrate having an adhesive layer on one side, low-boiling point impurities contained in the organic solvent (b) may penetrate from the decorative layer to the adhesive layer on the back, potentially deteriorating the adhesion of the adhesive layer (adhesion between the recorded material and the substrate). In addition, low-boiling point impurities contained in the organic solvent (b) may cause problems such as dissolution or swelling of plastics and adhesives used in printer components such as inkjet heads. By pre-mixing the organic solvent (b) with other components so that the content of impurities derived from the organic solvent (b) is 0.5% by mass or less of the total amount of organic solvent (b), the above problems can be solved, resulting in a non-aqueous ink composition that further enhances the effects of the present invention.

[0132] Methods for purifying organic solvent (b) include repeatedly distilling organic solvent (b), reducing the temperature increment of the distillation to minimize the inclusion of impurities, and repeatedly extracting the solvent. Furthermore, in industrial manufacturing processes, this can be achieved by adding measures to suppress contamination in addition to the above-mentioned processes.

[0133] (Other organic solvents) The organic solvent may contain organic solvents other than the organic solvent (b) described above. Specifically, examples include glycol ether dialkyls in which both terminal OH groups of the glycol are alkyl-substituted, glycol ether monoalkyls in which one of the OH groups of the glycol is alkyl-substituted, and carbonate esters.

[0134] Examples of glycol ether dialkyls include glycol ether dialkyls represented by the following formula (1).

[0135] [ka] (In formula (1), R1 and R3 are alkyl groups, and R2 represents an ethylene group or a propylene group. n represents an integer between 2 and 4.)

[0136] Specifically, glycol ether dialkyls include ethylene glycol dibutyl ether, ethylene glycol dipropyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dipropyl ether, diethylene glycol propyl methyl ether, diethylene glycol isopropyl methyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, diethylene glycol butyl ethyl ether, diethylene glycol methyl-2-ethylhexyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol ethyl methyl ether, and tetraethylene glycol dimethyl ether. Examples include tetraethylene glycol diethyl ether, tetraethylene glycol ethyl methyl ether, propylene glycol diethyl ether, propylene glycol ethyl methyl ether, propylene glycol methyl propyl ether, propylene glycol methyl butyl ether, propylene glycol methyl-2-ethylhexyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol ethyl methyl ether, dipropylene glycol methyl propyl ether, dipropylene glycol dipropyl ether, dipropylene glycol methyl butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, and tripropylene glycol ethyl methyl ether.

[0137] Among glycol ether dialkyls, glycol ether dialkyls in which the total number of carbon atoms in R1 and R3 in formula (1) is 2 or more and 8 or less are preferred, glycol ether dialkyls in which the total number of carbon atoms in R1 and R3 in formula (1) is 2 or more and 6 or less are more preferred, glycol ether dialkyls in which R1 in formula (1) is a methyl group or an ethyl group and R3 is an ethyl group, and / or glycol ether dialkyls in which R1 and R3 in formula (1) are methyl groups and R2 is a propylene group are even more preferred.

[0138] Glycol ether dialkyls in which the total number of carbon atoms in R1 and R3 is between 2 and 6 have higher volatility compared to, for example, diethylene glycol dibutyl ether (where the total number of carbon atoms in R1 and R3 is 8), resulting in a non-aqueous ink composition with excellent recording drying properties.

[0139] Examples of glycol ether dialkyls in which the total number of carbon atoms in R1 and R3 is between 2 and 6 include diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol isopropyl methyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and tetraethylene glycol diethyl ether.

[0140] Furthermore, glycol ether dialkyls in formula (1) where R1 is a methyl or ethyl group and R3 is an ethyl group, and / or glycol ether dialkyls in formula (1) where R1 and R3 are methyl groups and R2 is a propylene group, have even lower permeability compared to, for example, diethylene glycol dimethyl ether (where R1 and R3 are methyl groups and R2 is an ethylene group). For this reason, even when, for example, a resin substrate having an adhesive layer on one side is used to record (print) a non-aqueous ink composition on the substrate surface on the side without the adhesive layer, deterioration of the adhesive layer's adhesion (adhesion between the recording and the substrate) can be more effectively suppressed.

[0141] Examples of glycol ether dialkyls in formula (1) where R1 is a methyl or ethyl group and R3 is an ethyl group include diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, and tetraethylene glycol diethyl ether. An example of a glycol ether dialkyl in formula (1) where R1 and R3 are methyl groups and R2 is a propylene group is dipropylene glycol dimethyl ether.

[0142] Furthermore, glycol ether dialkyls are prone to generating impurities such as polymers, by-reaction products, and decomposition products during the manufacturing process. For example, commercially available glycol ether dialkyls may contain impurities of about 10% by mass of the total glycol ether dialkyl content. Therefore, it is preferable to pre-mix the glycol ether dialkyl with other components so that the impurity content derived from the glycol ether dialkyl is 0.5% by mass or less of the total glycol ether dialkyl content. Low-boiling point impurities contained in glycol ether dialkyls can worsen the odor. Also, for example, when a non-aqueous ink composition is recorded on a resin substrate having an adhesive layer on one side, low-boiling point impurities contained in glycol ether dialkyls may penetrate from the decorative layer to the adhesive layer on the back, worsening the adhesion of the adhesive layer (adhesion between the recorded material and the substrate). In addition, low-boiling point impurities contained in glycol ether dialkyls may cause problems such as dissolution or swelling in plastics and adhesives used in printer components such as inkjet heads. Furthermore, if the impurities contained in glycol ether dialkyls have high boiling points, the recording drying properties of the non-aqueous ink composition may decrease, causing printing smudging. By pre-treating the glycol ether dialkyl so that the amount of impurities derived from the glycol ether dialkyl is 0.5% by mass or less of the total amount of glycol ether dialkyl before mixing it with other components, the above problems can be solved, resulting in a non-aqueous ink composition that further exhibits the effects of the present invention.

[0143] The impurities contained in the glycol ether dialkyl are the same as those contained in the organic solvent (a) in the non-aqueous ink composition of the first embodiment described above. The purification method is also the same.

[0144] When glycol ether dialkyl is included, there is no particular lower limit to the glycol ether dialkyl content, but it is preferably 30.0% by mass or more, more preferably 40.0% by mass or more, and even more preferably 50.0% by mass or more in the total amount of the non-aqueous ink composition.

[0145] There is no particular upper limit to the glycol ether dialkyl content, but it is preferable that it be contained in 90.0% by mass or less of the total amount of the non-aqueous ink composition, and more preferably 80.0% by mass or less.

[0146] Examples of glycol ether monoalkyls include ethylene glycol mono-n-butyl ether, ethylene glycol mono-isobutyl ether, ethylene glycol mono-t-butyl ether, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl ether), triethylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl) ether, and tetraethylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl) ether. Examples include propylene glycol mono-n-butyl ether, propylene glycol mono-isobutyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-2-ethylhexyl ether, dipropylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl) ether, tripropylene glycol monomethyl (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl) ether, tetrapropylene glycol monomethyl ether (or ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl), etc.

[0147] Examples of carbonate esters include ethylene carbonate and propylene carbonate.

[0148] Furthermore, it may contain organic solvents other than those listed above. Specifically, cyclic esters such as γ-butyrolactone, γ-valerolactone, γ-hexalactone, γ-heptalactone, γ-octaractone, γ-nonalactone, γ-decalactone, and γ-undecalactone; oxazolidinone solvents such as 3-methyl-2-oxazolidinone, 3-ethyl-2-oxazolidinone, and N-vinylmethyloxazolidinone; triethylene glycol butyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol butyl ether acetate, propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, 1-methoxy-2-propyl acetate, 2-methylbutyl acetate, 3-methoxybutyl ether acetate, and cyclohexyl butyl ether acetate. Acetate solvents such as ammonium acetate; amide solvents different from alkylamide solvents (b1) and cyclic amide solvents (b2), such as 3-methoxypropanamide, 3-butoxypropanamide, N,N-dimethyl-3-methoxypropanamide, N,N-dibutyl-3-methoxypropanamide, N,N-dibutyl-3-butoxypropanamide, and N,N-dimethyl-3-butoxypropanamide; alkyl alcohols with 1 to 5 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, and n-pentanol; monohydric alcohol solvents such as 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-propanol, 1-methoxy-2-propanol, and 3-methoxy-n-butanol;Ketones or ketos such as acetone, diacetone alcohol, methyl ethyl ketone, methyl-n-propyl ketone, methyl isopropyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, methyl-n-amyl ketone, methylhexyl ketone, methyl isoamyl ketone, diethyl ketone, ethyl-n-propyl ketone, ethyl isopropyl ketone, ethyl-n-butyl ketone, ethyl isobutyl ketone, di-n-propyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, isophorone, acetyl ketone, etc. Glycols; ethers such as tetrahydrofuran and dioxane; oxyethylene or oxypropylene copolymers such as polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-propanediol, isobutylene glycol, triethylene glycol, tripropylene glycol, tetraethylene glycol, 1,3-propanediol, 2-methyl-1,2-propanediol, 2-methyl-1,2-propanediol, 1,2-butanediol, 1,3 Diols such as -butanediol, 1,4-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-butanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol; triols such as glycerin, trimethylolethane, trimethylolpropane, 1,2,6-hexanetriol; tetrahydric alcohols such as mesoerythritol and pentaerythritol; monoethanolamine Alkanolamines such as diethanolamine, triethanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, and N-butyldiethanolamine; Acetate esters such as methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, hexyl acetate, and octyl acetate; Lactic acid esters such as methyl lactate, ethyl lactate, butyl lactate, propyl lactate, ethylhexyl lactate, amyl lactate, and isoamyl lactate;Examples include saturated hydrocarbons such as n-hexane, isohexane, n-nonane, isononane, dodecane, and isododecane; unsaturated hydrocarbons such as 1-hexene, 1-heptene, and 1-octene; cyclic unsaturated hydrocarbons such as cyclohexene, cycloheptene, cyclooctene, 1,1,3,5,7-cyclooctatetraene, and cyclododecene; aromatic hydrocarbons such as benzene, toluene, and xylene; morpholins such as N-methylmorpholine, N-ethylmorpholine, and N-formylmorpholine; terpene solvents; and dibasic acid esters such as dimethyl oxalate, diethyl oxalate, dimethyl malonate, diethyl malonate, dipropyl malonate, dimethyl succinate, diethyl succinate, dimethyl glutarate, and diethyl glutarate. It is preferable to select a solvent with an appropriate HLB value depending on the resin and dispersant being combined.

[0149] Furthermore, a five-membered ring lactone solvent may be contained, but it is preferable that it is not contained. If a five-membered ring lactone solvent is contained, the content of the five-membered ring lactone solvent is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 1.0% by mass or less, and still more preferably not contained at all.

[0150] Examples of five-membered ring lactone solvents include γ-butyrolactone, γ-valerolactone, γ-hexanolactone, and γ-heptanolactone.

[0151] [Colorants] The colorants are the same as those included in the non-aqueous ink composition of the first embodiment described above. The preferred pigment content is also the same.

[0152] [resin] The non-aqueous ink composition according to this embodiment is characterized by containing a resin having a weight-average absolute molecular weight of 15,000 to 80,000. This effectively suppresses whitening of the decorative layer even when the recorded material is stretched. Although resins with such high weight-average absolute molecular weights have low solubility in organic solvents, the non-aqueous ink composition according to this embodiment, which contains at least one organic solvent (b) selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with six or more membered rings (b3), makes it possible to dissolve resins with high weight-average absolute molecular weights. This allows for the effective suppression of whitening of the decorative layer while maintaining storage stability and discharge stability.

[0153] Here, weight-average absolute molecular weight refers to the weight-average absolute molecular weight determined by the gel permission chromatography-multi-angle light cutting (GPC-MALS) method. The weight-average absolute molecular weight can be measured using a GPC (Waters, Alliance GPC) equipped with a TSKgel column (Tosoh Corporation) and a multi-angle light scattering detector (Wyatt, miniDawn TREOS), with THF as the developing solvent. This weight-average absolute molecular weight is different from the weight-average relative molecular weight obtained by the conventional GPC method using polystyrene equivalent values ​​(relative values).

[0154] The weight-average relative molecular weight, calculated using polystyrene equivalent values ​​(relative values), cannot always accurately measure the molecular weight or gel component amount in the resin being measured due to differences in molecular structure between the resin being measured and the standard substance, polystyrene, as well as the effects of column adsorption. Therefore, the weight-average absolute molecular weight measured by GPC equipped with a predetermined column and multi-angle light scattering detector can serve as an indicator of the resin's inherent weight-average molecular weight.

[0155] The weight-average absolute molecular weight of the resin is not particularly limited as long as it is in the range of 15,000 to 80,000, but the lower limit of the weight-average absolute molecular weight of the resin is preferably 25,000 or more, and more preferably 32,500 or more. This makes it possible to further improve the stretchability of the decorative layer and effectively suppress whitening of the decorative layer.

[0156] The upper limit of the weight-average absolute molecular weight of the resin is preferably 70,000 or less, and more preferably 50,000 or less. Since the ejection stability of the non-aqueous ink composition is improved, for example, when the non-aqueous ink composition is a non-aqueous inkjet ink composition ejected onto the surface of a substrate using an inkjet method, the print quality can be improved.

[0157] There are no particular limitations on the resin used; for example, acrylic resins, polystyrene resins, polyester resins, vinyl chloride resins, vinyl acetate resins, vinyl chloride acetate resins, polyethylene resins, polyurethane resins, rosin-modified resins, phenolic resins, terpene resins, polyamide resins, vinyltoluene-α-methylstyrene copolymers, ethylene-vinyl acetate copolymers, cellulose acetate butyrate, cellulose acetate propionate, silicone resins, acrylamide resins, epoxy resins, or copolymers or mixtures thereof can be used.

[0158] In the non-aqueous ink composition according to this embodiment, it is preferable that it contains at least one selected from the group consisting of acrylic resins, vinyl chloride resins, and cellulose resins, in order to improve water resistance, solvent resistance, and stretchability. Furthermore, when used as an inkjet ink, it can improve ejection response and ejection stability during high-speed recording.

[0159] The acrylic resin is not particularly limited as long as it is included as a main component of the monomer constituting the (meth)acrylic acid ester monomer, and examples similar to those of the non-aqueous ink composition described above can be given. The acrylic resin may be a homopolymer of one radical polymerizable monomer, or a copolymer using two or more radical polymerizable monomers selected from each other. In particular, preferred acrylic resins for the non-aqueous ink composition of this embodiment are a polymer of methyl methacrylate alone, or a copolymer of methyl methacrylate and at least one compound selected from the group consisting of butyl methacrylate, ethoxyethyl methacrylate, and benzyl methacrylate.

[0160] The vinyl chloride resin may be either a homopolymer composed of vinyl chloride monomers or a copolymer using two or more polymerizable monomers selected from each other. Examples of vinyl chloride polymers include vinyl chloride-vinyl acetate copolymer resins. Vinyl chloride-vinyl acetate copolymer resins are polymers of vinyl chloride monomers and vinyl acetate monomers. Examples of vinyl chloride-vinyl acetate copolymer resins include vinyl chloride-vinyl acetate copolymers, vinyl chloride / vinyl acetate / maleic acid copolymers, vinyl chloride / vinyl acetate / vinyl alcohol copolymers, vinyl chloride / vinyl acetate / hydroxyalkyl acrylate copolymers, and mixtures thereof.

[0161] Cellulose resins are resins having a cellulose skeleton obtained by introducing functional groups biologically or chemically into cellulose as a raw material. Examples of cellulose resins include cellulose acetate alkylate resins such as cellulose acetate butyrate resin, cellulose acetate propionate resin, and cellulose acetate propionate butyrate resin, as well as cellulose acetate resins, nitrocellulose resins, and mixtures thereof.

[0162] The resin content in the total amount of the non-aqueous ink composition according to this embodiment is not particularly limited, but for example, it is preferably 0.05% by mass or more in the total amount of the non-aqueous ink composition, more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, and more preferably 1% by mass or more. The mass percentage of resin in the total amount of the non-aqueous ink composition is not particularly limited, but for example, it is preferably 20% by mass or less in the non-aqueous ink composition, and more preferably 15% by mass or less.

[0163] [Dispersant] The dispersant is the same as the dispersant included in the non-aqueous ink composition of the first embodiment described above.

[0164] [Dispersing agent] The dispersion aid is the same as the dispersion aid included in the non-aqueous ink composition of the first embodiment described above.

[0165] [Surfactants] The surfactant is the same as the surfactant included in the non-aqueous ink composition of the first embodiment described above.

[0166] [Other ingredients] The non-aqueous ink composition according to this embodiment may optionally contain known additives such as antioxidants, UV absorbers and other stabilizers, epoxidants and other polycarboxylic acids, surface modifiers, leveling agents (acrylic or silicone-based, etc.), defoamers, pH adjusters, bactericides, preservatives, deodorants, charge adjusters, and wetting agents. The other components are the same as those contained in the non-aqueous ink composition of the first embodiment described above.

[0167] [Base material] As the substrate (recording medium) that can be used in the non-aqueous ink composition according to this embodiment, the same substrate (recording medium) that can be used in the non-aqueous ink composition of the first embodiment described above can be used.

[0168] Furthermore, by using the non-aqueous ink composition according to this embodiment on a resin substrate (a resin substrate for lamination) having an adhesive layer on one side, it is possible to more effectively suppress film peeling and deterioration of the adhesiveness of the adhesive layer (adhesion between the recorded material and the substrate). For this reason, the substrate (recording medium) used in the non-aqueous ink composition according to this embodiment is not particularly limited, but it is preferable to use it on a resin substrate having an adhesive layer on one side, and it is particularly preferable to use it on a polyvinyl chloride substrate having an adhesive layer on one side.

[0169] <Recording method using ink composition> The recording method for recording on the surface of a substrate (recording medium) using the non-aqueous ink composition according to this embodiment (the non-aqueous ink composition of the first embodiment or the non-aqueous ink composition of the second embodiment described above) is not particularly limited. Examples include spray method, coater method, inkjet method, gravure method, flexographic method, etc.

[0170] In particular, it is preferable that the ink is ejected onto the surface of the substrate using an inkjet method. The non-aqueous ink composition according to this embodiment exhibits little dissolution or swelling in plastic components or adhesives, and therefore has good compatibility with inkjet heads and other components, which can be a problem for non-aqueous ink compositions for inkjet applications. Furthermore, since the non-aqueous ink composition of the first embodiment described above has good drying properties, it is possible to efficiently manufacture records with good post-processing properties using an inkjet method.

[0171] Inkjet printers used in the inkjet method can be conventionally known models. For example, inkjet printers such as the VersaArt RE-640 manufactured by Roland DG Corporation can be used.

[0172] Furthermore, the non-aqueous ink composition according to this embodiment can be used for various ink colors such as yellow, magenta, cyan, and black, as well as light magenta, light cyan, light black, orange, green, red, and white, and there are no particular restrictions on the order of colors to be printed or the position and configuration of the print head. In addition, the inkjet printer may or may not be equipped with a recording medium (substrate) winding mechanism, a drying mechanism for drying the substrate surface, and an ink circulation mechanism.

[0173] <Records and methods for manufacturing records> Recordings can also be manufactured using the non-aqueous ink composition according to this embodiment (the non-aqueous ink composition of the first embodiment or the non-aqueous ink composition of the second embodiment described above). The method of manufacturing the recordings is not particularly limited and can be manufactured by the method exemplified in the recording method using the above ink composition. In particular, it is preferable to eject the ink onto the surface of the substrate using an inkjet method.

[0174] The non-aqueous ink composition of the first embodiment described above has high drying properties on the substrate surface and good post-processing properties for the resulting recorded material. Therefore, if a laminate (recorded material) is formed by applying (dispensing) the non-aqueous ink composition according to this embodiment to the surface of the resin substrate opposite the adhesive layer using a resin substrate for lamination, and then equipping the surface of the decorative layer with a laminate film, the lifting of the bonded film can be effectively suppressed, resulting in good post-processing properties for the recorded material.

[0175] Since the non-aqueous ink composition of the second embodiment described above does not have high permeability to the resin substrate, even when recording (printing) the non-aqueous ink composition according to this embodiment on the surface of the substrate that does not have the adhesive layer, for example, when using a resin substrate that has an adhesive layer on one side, deterioration of the adhesiveness of the adhesive layer (adhesion between the recorded material and the substrate) can be suppressed.

[0176] Furthermore, if the non-aqueous ink composition of the second embodiment contains at least one organic solvent (b) selected from the group consisting of alkylamide solvents (b1), cyclic amide solvents (b2), and lactone solvents with six or more membered rings (b3), it becomes possible to dissolve resins with high weight-average absolute molecular weight. Therefore, while maintaining the storage stability and ejection stability that can be problematic for inkjet ink compositions, it is possible to effectively suppress whitening of the decorative layer even when the recorded material is stretched by containing a resin with high weight-average absolute molecular weight. [Examples]

[0177] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way to these descriptions.

[0178] [Non-aqueous ink composition of the first embodiment] 1. Preparation of resin (1) Acrylic resin To 300 g of diethylene glycol diethyl ether maintained at 100°C, a mixture of 150 g of methyl methacrylate, 50 g of butyl methacrylate, and 1.2 g of a predetermined amount of t-butyl peroxy-2-ethylhexanoate (polymerization initiator) was added dropwise over 1.5 hours. After the addition was complete, the mixture was reacted at 100°C for 2 hours and then cooled to obtain a colorless, transparent polymer solution of methyl methacrylate (solid content 39.5%). The solvent was then thoroughly removed from this polymer solution. At this time, the average polymerization molecular weight (polystyrene equivalent) of methyl methacrylate (acrylic resin) was 30,000 (indicated as "acrylic resin" in the table).

[0179] (2) Vinyl chloride-vinyl acetate copolymer resin In an autoclave equipped with a stirring device, after purging with nitrogen, 100 parts deionized water, 40 parts methanol, 32 parts vinyl chloride, 5 parts vinyl acetate, 0.2 parts glycidyl methacrylate, 3.55 parts hydroxypropyl acrylate, 0.1 part hydroxypropyl methylcellulose (suspending agent), 0.026 parts di-2-ethylhexyl peroxydicarbonate (polymerization initiator), and a predetermined amount of di-3,5,5-trimethylhexanol peroxide (polymerization initiator) were charged. The mixture was heated to 63°C while stirring under a nitrogen gas atmosphere. Immediately after reaching 63°C, 48 parts vinyl chloride was continuously injected over 6 hours, and a mixture of 0.6 parts glycidyl methacrylate and 10.65 parts hydroxypropyl acrylate was continuously injected over 5.4 hours to induce a copolymerization reaction. When the internal pressure of the autoclave reached 0.3 MPa, the remaining pressure was released, the mixture was cooled, and the resin slurry was extracted, filtered, and dried to obtain a vinyl chloride copolymer resin. At this time, the amount of di-3,5,5-trimethylhexanol peroxide, which is the polymerization initiator, was changed to control the average polymerization molecular weight (polystyrene equivalent) of the vinyl chloride-vinyl acetate copolymer resin to be between 35,000 and 75,000 (indicated as "vinyl chloride-vinyl acetate copolymer 1-3" in the table).

[0180] [Table 1]

[0181] 2. Preparation of non-aqueous ink compositions Non-aqueous ink compositions for Example A and Comparative Example A were prepared according to the proportions of each component shown in the table below. Specifically, the non-aqueous ink compositions were prepared by dispersing each component with zirconia beads using a paint shaker. The unit is parts by mass. Note that the impurities of organic solvents (a) and (b) used in Examples 1-69 were determined by gas chromatography before mixing.

[0182] [evaluation] (Drying time for recording) The drying properties of the non-aqueous ink compositions of Example A and Comparative Example A were evaluated. Specifically, the non-aqueous ink compositions of Example A and Comparative Example A were printed as solid images on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R: MACtac)) using an inkjet method with an inkjet printer (product name VersaArt RE-640, manufactured by Roland DG Corporation) in high-quality printing mode (1440x720dpi), and the time it took to dry at 40°C was measured (indicated as "Recording Drying Properties" in the table). Evaluation Criteria Rating 5: Dries in less than 2 minutes. Rating 4: Dries in between 2 and 4 minutes. Rating 3: Dries in 4 to 6 minutes. Rating 2: Dries in 6 to 8 minutes. Rating 1: Dries in over 8 minutes.

[0183] (Material suitability) The non-aqueous ink compositions of Example A and Comparative Example A were evaluated for their suitability as components (suitability as components for inkjet heads). Specifically, 0.2 g of the cured epoxy adhesive (two-component curing epoxy adhesive "1500", manufactured by Cemedyne Co., Ltd.), which is used as a component for inkjet heads, was dried at 60°C for one day. This cured product was then immersed in the ink compositions of Example A and Comparative Example A, left at 60°C for one week, and an immersion test was conducted, measuring the weight change of the cured product (indicated as "Component Suitability" in the table). Evaluation Criteria Rating 5: Weight change rate is less than 3%, and there is no degradation of the epoxy adhesive material. Rating 4: The weight change rate is between 3% and 5%, and there is no degradation of the epoxy adhesive material. Rating 3: Weight change rate is between 5% and 10%, and there is no degradation of the epoxy adhesive material. Evaluation 2: The weight change rate is between 10% and 15%, and there is no degradation of the epoxy adhesive material. Evaluation 1: Weight change rate is 15% or more and / or there is deterioration of the epoxy adhesive material.

[0184] (post-processability) The post-processing properties of the non-aqueous ink compositions of Example A and Comparative Example A were evaluated. Similar to the recording drying performance evaluation described above, a 30cm x 30cm solid image with 100% magenta density was printed on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R: manufactured by MACtac)) in high-quality printing mode (1440x720dpi) at a substrate surface temperature of 40°C. Immediately after printing, a laminate film (LL Glossy Lami S: manufactured by Sakurai Co., Ltd.) was applied to the entire recording surface of the recording material and left for one day. The area of ​​the peeled film was then checked. The results of the evaluation according to the following evaluation criteria are shown in Table 1 below (in Table 1, "Post-processing properties" is used). Evaluation Criteria Rating 5: Film delamination rate is 0%. Rating 4: Film delamination is between 0% and less than 3%. Rating 3: Film delamination is between 3% and 5%. Evaluation 2: Film delamination is between 5% and 10%. Evaluation 1: More than 10% of the film is peeled off.

[0185] (Storage stability) The storage stability of the non-aqueous ink compositions of Example A and Comparative Example A was evaluated. Specifically, the non-aqueous ink compositions were stored at 60°C for one month, and the changes in viscosity and the volume-average particle size (D50) of the pigment before and after the test were observed. The storage stability was evaluated according to the following criteria. The viscosity of the ink was measured at 20°C using a falling-ball viscometer (AMVn, manufactured by Anton Paar), and the volume-average particle size (D50) of the pigment was measured at 25°C using a particle size distribution analyzer (NANOTRACWAVE, manufactured by Microtrac Bell Co., Ltd.). In the evaluation below, the non-aqueous ink composition was evaluated based on the larger change rate between "viscosity" and "volume-average particle size of the pigment". Evaluation Criteria Rating 5: The rate of change in viscosity and the volume-average particle size of the pigment are both less than 3%. Evaluation 4: The rate of change in either viscosity or the volume-average particle size of the pigment is between 3% and 5%. Evaluation 3: The rate of change in viscosity or the volume-average particle size of the pigment is between 5% and 8%. Evaluation 2: The rate of change in viscosity or the volume-average particle size of the pigment is 8% or more but less than 10%. Evaluation 1: The rate of change in either viscosity or the volume-average particle size of the pigment is 10% or more.

[0186] (Evaluation of bleeding properties) In the same manner as the recording drying performance evaluation described above, images with 6pt characters of a different color within solid areas of each color were printed on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R: manufactured by MACtac)) in high-quality printing mode (1440x720dpi) at a substrate surface temperature of 40°C. The resulting recordings were dried in a 60°C oven for 5 minutes, and the bleeding of the recordings was observed visually. Evaluation Criteria Rating 4: No ink bleeding was observed, and 6pt lettering is clear. Rating 3: Slight ink bleeding was observed, but the design was not compromised. Evaluation 2: Ink bleeding was observed, but 6pt letters are legible. Rating 1: Significant ink bleeding was observed, making the 6pt text illegible.

[0187] [Table 2]

[0188] [Table 3]

[0189] [Table 4]

[0190] As can be seen from the table above, the non-aqueous ink composition of Example A, containing organic solvent (a) and organic solvent (b), exhibits high recording drying properties on the substrate surface and good post-processing properties for the resulting recording. Furthermore, the non-aqueous ink composition of Example A, containing organic solvent (a) and organic solvent (b), also showed good material suitability, storage stability, and bleed resistance. And, as shown in Examples 55-69, even when various colorants were included, the results were comparable to those of Example 20, which contained carbon black.

[0191] Furthermore, when comparing non-aqueous ink compositions containing, for example, 15.0% by mass of organic solvent (b) in the total amount of the non-aqueous ink composition, with Example 20 (containing alkylamide solvent (b1)), Example 24 (containing alkylamide solvent (b1)), Example 30 (containing cyclic amide solvent (b2)), Example 32 (containing cyclic amide solvent (b2)), Example 33 (containing cyclic amide solvent (b2)), Example 34 (containing lactone solvent (b3) with 6 or more membered rings), Example 35 (containing lactone solvent (b3) with 6 or more membered rings), and Example 39 (containing lactone solvent (b3) with 6 or more membered rings), Examples 20, 24, 30, 32, and 33, which contain alkylamide solvent (b1) or cyclic amide solvent (b2) as organic solvent (b), showed better recording drying performance compared to Examples 34, 35, and 39.

[0192] Furthermore, comparing Examples 17 to 21, which contain, for example, N,N-diethylformamide (alkylamide solvent (b1)) as the organic solvent (b), Examples 20 and 21, which contain organic solvent (b) in a proportion of 17.0% by mass or less, showed particularly good material suitability and post-processability.

[0193] Furthermore, the non-aqueous ink composition of Example 30 had a lower water content, better recording drying properties on the substrate surface, and good storage stability compared to Example 51 with the same composition ratio. In addition, the non-aqueous ink composition of Example 30 had a lower concentration of impurities derived from organic solvent (a) and organic solvent (b) compared to Example 52 with the same composition ratio, had better drying properties on the substrate surface, and the resulting recorded material had good post-processing properties.

[0194] Furthermore, compared to Example 45, which contains diethylene glycol dibutyl ether as organic solvent (a), Example 20, which contains diethylene glycol methyl ethyl ether as organic solvent (a), Example 44, which contains diethylene glycol diethyl ether as organic solvent (a), and Example 46, which contains dipropylene glycol dimethyl ether as organic solvent (a), showed particularly good record-drying properties.

[0195] On the other hand, the non-aqueous ink composition of Example 70, which did not contain organic solvent (b) or a five-membered ring lactone solvent, had poor recording drying properties and also exhibited bleeding. Furthermore, the non-aqueous ink compositions of Examples 71 to 75, which contained a five-membered ring lactone solvent or 3-methoxy-N,N-dimethylpropanamide instead of organic solvent (b), showed less bleeding but poor post-processing properties. In addition, the non-aqueous ink compositions of Examples 76 to 81, which did not contain organic solvent (a), had poor recording drying properties and material suitability.

[0196] [Non-aqueous ink composition of the second embodiment] 1. Preparation of resin (1) Acrylic resin A mixture of 150 g of methyl methacrylate, 50 g of butyl methacrylate, and a predetermined amount of t-butyl peroxy-2-ethylhexanoate (polymerization initiator) was added dropwise to 300 g of diethylene glycol diethyl ether maintained at 100°C over 1.5 hours. After the addition was complete, the mixture was reacted at 100°C for 2 hours and then cooled to obtain a colorless, transparent polymer solution of methyl methacrylate (solid content 39.5%). The solvent was then thoroughly removed from this polymer solution. The average absolute molecular weight of the polymerized methyl methacrylate (acrylic resin) was controlled by changing the amount of t-butyl peroxy-2-ethylhexanoate, the polymerization initiator (the mass of the polymerization initiator used is listed in Table 1 below, labeled "Initiator Amount"). The weight-average absolute molecular weight was measured using a GPC equipped with a TSKgel column (Tosoh Corporation) and a multi-angle light scattering detector (Wyatt, miniDawn TREOS). THF was used as the developing solvent.

[0197] (2) Vinyl chloride-vinyl acetate copolymer resin In an autoclave equipped with a stirring device, after purging with nitrogen, 100 parts deionized water, 40 parts methanol, 32 parts vinyl chloride, 5 parts vinyl acetate, 0.2 parts glycidyl methacrylate, 3.55 parts hydroxypropyl acrylate, 0.1 part hydroxypropyl methylcellulose (suspending agent), 0.026 parts di-2-ethylhexyl peroxydicarbonate (polymerization initiator), and a predetermined amount of di-3,5,5-trimethylhexanol peroxide (polymerization initiator) were charged. The mixture was heated to 63°C while stirring under a nitrogen gas atmosphere. Immediately after reaching 63°C, 48 parts vinyl chloride was continuously injected over 6 hours, and a mixture of 0.6 parts glycidyl methacrylate and 10.65 parts hydroxypropyl acrylate was continuously injected over 5.4 hours to induce a copolymerization reaction. When the internal pressure of the autoclave reached 0.3 MPa, the remaining pressure was released, the mixture was cooled, and the resin slurry was extracted, filtered, and dried to obtain a vinyl chloride copolymer resin. At this time, the average absolute molecular weight of the vinyl chloride-vinyl acetate copolymer resin was controlled by changing the amount of di-3,5,5-trimethylhexanol peroxide, which is the polymerization initiator (the mass of the polymerization initiator used at this time is listed in Table 1 below. In Table 1, it is written as "Amount of Initiator"). The weight-average absolute molecular weight was measured by GPC equipped with a TSKgel column (Tosoh Corporation) and a multi-angle light scattering detector (Wyatt, miniDawn TREOS). THF was used as the developing solvent.

[0198] (3) Cellulose resins Commercially available cellulose-based resins (EASTMAN CHEMICAL's CAP-482-0.5, CAB553-0.4, CAB551-0.01) were used.

[0199] Table 5 shows the weight-average absolute molecular weight of each resin (acrylic resin, vinyl chloride-vinyl acetate copolymer resin, and cellulose-based resin).

[0200] [Table 5]

[0201] 2. Preparation of non-aqueous ink composition Non-aqueous ink compositions for Example B and Comparative Example B were prepared according to the proportions of each component as shown in Table 6 below. Specifically, the non-aqueous ink compositions were prepared by dispersing each component with zirconia beads using a paint shaker. The unit is parts by mass. The impurity concentrations of the organic solvent (b) and glycol ether dialkyl used in Examples 1 to 69 were determined by gas chromatography before mixing.

[0202] [evaluation] (Drying time for recording) The drying properties of the non-aqueous ink compositions of Example B and Comparative Example B were evaluated. Specifically, the non-aqueous ink compositions of Example B and Comparative Example B were printed as solid images on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R: MACtac)) using an inkjet method with an inkjet printer (product name VersaArt RE-640, manufactured by Roland DG Corporation) in high-quality print mode (1440x720dpi), and the time it took to dry at 40°C was measured (indicated as "Recording Drying Properties" in the table). Evaluation Criteria Rating 5: Dries in less than 2 minutes. Rating 4: Dries in between 2 and 4 minutes. Rating 3: Dries in 4 to 6 minutes. Rating 2: Dries in 6 to 8 minutes. Rating 1: Dries in over 8 minutes.

[0203] (Original glue adhesive strength) The adhesion properties of the non-aqueous ink compositions of Example B and Comparative Example B were evaluated. Specifically, similar to the recording drying performance evaluation described above, a solid image printed on a recording medium (adhesive-backed polyvinyl chloride film (3M Controltac Graphic Film IJ180: manufactured by 3M)) in high-quality printing mode (1440x720dpi) at a substrate surface temperature of 40°C was attached to an aluminum plate (substrate), and after 1 hour, a peel strength test was performed using an A&D Corporation TSNSILON RTG1250 tensile testing machine. The test was performed using a 50N load cell at a speed of 5 mm / s. The results evaluated according to the following evaluation criteria are shown in Table 1 below (in Table 1, this is indicated as "Adhesion Strength of Base Material Adhesive"). Rating 5: 5N / 20mm or more Rating 4: 4N / 20mm or more, 5N / less than 20mm Rating 3: 3N / 20mm or more, 4N / less than 20mm Rating 2: 2N / 20mm or more, 3N / less than 20mm Rating 1: 2N / 20mm or less

[0204] (Odor test) Similar to the recording drying performance evaluation described above, six subjects smelled the recording immediately after printing on a recording medium (adhesive-backed polyvinyl chloride film (IMAGin JT5829R: manufactured by MACtac)) in high-quality printing mode (1440x720dpi) at a substrate surface temperature of 40°C. The most frequent evaluation was used as the evaluation of the non-aqueous ink composition (indicated as "Odor" in the table). Rating 5: No unpleasant odor. Rating 4: Has a slight odor. Rating 3: I can smell an odor. Rating 2: Has a slightly unpleasant odor. Rating 1: Has an unpleasant odor.

[0205] (Storage stability) The storage stability of the non-aqueous ink compositions of Example B and Comparative Example B was evaluated. Specifically, the non-aqueous ink compositions of Example B and Comparative Example B were stored at 60°C for one month, and the changes in viscosity and the average particle size (D50) of the pigment before and after the test were observed. The storage stability was evaluated according to the following criteria. The viscosity of the ink was measured at 20°C using a falling-ball viscometer (AMVn, manufactured by Anton Paar), and the volume-average particle size (D50) of the pigment was measured at 25°C using a particle size distribution analyzer (NANOTRACWAVE, manufactured by Microtrac Bell Co., Ltd.). In the evaluation below, the non-aqueous ink composition was evaluated based on the larger change rate between "viscosity" and "volume-average particle size of pigment". Evaluation Criteria Rating 5: The rate of change in viscosity and the volume-average particle size of the pigment are both less than 3%. Evaluation 4: The rate of change in either viscosity or the volume-average particle size of the pigment is between 3% and 5%. Evaluation 3: The rate of change in viscosity or the volume-average particle size of the pigment is between 5% and 8%. Evaluation 2: The rate of change in viscosity or the volume-average particle size of the pigment is 8% or more but less than 10%. Evaluation 1: The rate of change in either viscosity or the volume-average particle size of the pigment is 10% or more.

[0206] (Stretchability) The storage stability of the non-aqueous ink compositions of Example B and Comparative Example B was evaluated. Specifically, a recording was created by printing (recording) on ​​a polyvinyl chloride substrate using an inkjet printer. Similar to the recording drying evaluation described above, the recording was printed on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R: MACtac)) in high-quality printing mode (1440x720dpi) at a substrate surface temperature of 40°C. Immediately after printing, the solid magenta printing (recording) portion of the recording was stretched to 200% at room temperature. The decorative layers before and after stretching were tested using an x-rite eXact from X-Rite Corporation under the conditions of a D65 light source and a 2° viewing angle. * a * b * The following measurements were taken: L before and after the test.* The difference is ΔL * , the difference in a before and after the test * is Δa * , the difference in b before and after the test * is Δb * , when it is set as, ΔE = 〔(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2 〕 1 / 2 The evaluation was made based on ΔE calculated by Evaluation criteria Evaluation 5: ΔE is less than 7.5 Evaluation 4: ΔE is 7.5 or more and less than 10 Evaluation 3: ΔE is 10 or more and less than 12.5 Evaluation 2: ΔE is 12.5 or more and less than 15 Evaluation 1: ΔE is 15 or more

[0207] (Discharge stability) The discharge stability of the non-aqueous ink compositions of Example B and Comparative Example B was evaluated. Specifically, in the same manner as the above-described recording drying property evaluation, a thin line was printed on a recording medium (adhesive vinyl chloride film (IMAGin JT5829R: manufactured by MACtac)) in a bidirectional high-speed printing mode (360x720 dpi) at a substrate surface temperature of 40°C, and the evaluation was made by visual inspection and confirmation with a loupe (5 times magnification) (indicated as "discharge stability" in the table). Evaluation criteria Evaluation 4: The thin line can be correctly reproduced even when confirmed with a loupe Evaluation 3: It cannot be discriminated visually, but a slight bend can be recognized when confirmed with a loupe Evaluation 2: A slight bend can be recognized even visually Evaluation 1: A bend is clearly visible visually

[0208] (Bleeding property evaluation) In the same manner as the recording drying performance evaluation described above, images with 6pt characters of a different color within solid areas of each color were printed on a recording medium (adhesive polyvinyl chloride film (IMAGin JT5829R: manufactured by MACtac)) in high-quality printing mode (1440x720dpi) at a substrate surface temperature of 40°C. The resulting printed material was dried in a 60°C oven for 5 minutes, and the bleeding of the printed material was visually observed. Evaluation Criteria Rating 4: No ink bleeding was observed, and 6pt lettering is clear. Rating 3: Slight ink bleeding was observed, but the design was not compromised. Evaluation 2: Ink bleeding was observed, but 6pt letters are legible. Rating 1: Significant ink bleeding was observed, making the 6pt text illegible.

[0209] [Table 6]

[0210] [Table 7]

[0211] As can be seen from Tables 6 and 7, a non-aqueous ink composition containing an organic solvent (b) and a resin with a weight-average absolute molecular weight of 15,000 to 80,000 can effectively suppress deterioration of the adhesive layer's adhesion (adhesion between the recorded material and the substrate) and prevent whitening of the decorative layer even when the recorded material is stretched, even when using a resin substrate with an adhesive layer on one side and recording (printing) the non-aqueous ink composition on the substrate surface without the adhesive layer. The non-aqueous ink composition containing an organic solvent (b) and a resin with a weight-average absolute molecular weight of 15,000 to 80,000 also exhibited good recording drying properties, odor, storage stability, ejection stability, and bleeding properties. Furthermore, as shown in Examples 42 to 56, even when containing various colorants, the results were equivalent to those of Example 3, which contained carbon black.

[0212] Furthermore, when comparing, for example, Examples 3, 5, and 6 (containing alkylamide solvent (b1)), which contain 10.0% by mass of organic solvent (b) in the total amount of the non-aqueous ink composition, with Examples 7, 10, and 11 (containing cyclic amide solvent (b2)), and Examples 12, 13, and 16 (containing lactone solvent (b3) with 6 or more membered rings), Examples 3, 5, 6, 7, 10, and 11, which contain alkylamide solvent (b1) or cyclic amide solvent (b2) as organic solvent (b), showed superior adhesion strength to the base material compared to Examples 12, 13, and 16.

[0213] Furthermore, comparing Examples 1 to 4, which contain, for example, N,N-diethylformamide (alkylamide solvent (b1)) as the organic solvent (b), Examples 3 and 4, which contain organic solvent (b) in a proportion of 15.0% by mass or less, showed superior adhesion strength to the raw material adhesive.

[0214] Furthermore, comparing Examples 3, 17-19, and others that share common features except for containing resins with different weight-average absolute molecular weights, Examples 3, 17, and 18, where the weight-average absolute molecular weight of the resin is 25,000 or higher, exhibited superior stretchability. Among these, Examples 3 and 17, where the weight-average absolute molecular weight of the resin is 32,500 or higher, showed particularly excellent stretchability.

[0215] Furthermore, the non-aqueous ink composition of Example 3 had a lower water content compared to Example 37 with the same composition ratio, resulting in better storage stability and recording drying properties. In addition, the non-aqueous ink composition of Example 3 had a lower concentration of impurities derived from organic solvent (b) and glycol ether dialkyl compared to Example 38 with the same composition ratio, resulting in superior adhesion strength to the substrate adhesive, as well as good drying properties and odor.

[0216] On the other hand, Examples 61, 62, and 64, which contained resins with a weight-average absolute molecular weight exceeding 80,000, did not exhibit good discharge stability. Furthermore, Examples 63 and 65, which contained resins with a weight-average absolute molecular weight of less than 15,000, showed reduced stretchability. In addition, the non-aqueous ink compositions of Examples 66 to 70, which contained a five-membered ring lactone solvent or 3-methoxy-N,N-dimethylpropanamide instead of organic solvent (b), showed poor adhesion strength to the base material adhesive.

Claims

1. A non-aqueous ink composition containing an organic solvent, The aforementioned organic solvent contains the following organic solvent (a) and a lactone-based solvent (b3) with a ring of six or more members. The content of the aforementioned organic solvent (a) is 30.0% by mass or more of the total amount of the non-aqueous ink composition. Furthermore, it contains resin, The weight-average absolute molecular weight of the aforementioned resin is 15,000 or more and 80,000 or less. The content of the lactone-based solvent (b3) with six or more member rings is in the range of 3.0% by mass or more and 30.0% by mass or less of the total amount of the non-aqueous ink composition. The lactone-based solvent (b3) with six or more member rings is represented by the following general formula (4). Non-aqueous ink composition. Organic solvent (a): Glycol ether dialkyl 【Chemistry 1】 (In formula (4), R ８ This is an alkylene group with 5 carbon atoms, and R ９ (This represents hydrogen or an alkyl group having 1 to 2 carbon atoms.)

2. The organic solvent (a) is a glycol ether dialkyl represented by the following formula (1). The non-aqueous ink composition according to claim 1. 【Chemistry 2】 (In formula (1), R １ R ３ is an alkyl group, R ２ (where n represents an ethylene group or a propylene group, and n is an integer between 2 and 4.)

3. R in formula (1) １ and R ３ The total number of carbon atoms contained in it is between 2 and 6. The non-aqueous ink composition according to claim 2.

4. Organic solvent (a) is, R in the formula (1) １ is a methyl group or an ethyl group, and R in the formula (1) ３ is an ethyl group, or and / or R in formula (1) １ and R ３ is a methyl group and R ２ The propylene group The non-aqueous ink composition according to claim 3.

5. The content of impurities derived from the organic solvent (a) is 0.5% by mass or less of the total amount of the organic solvent (a), The content of impurities derived from the lactone solvent (b3) with six or more membered rings is 0.5% by mass or less of the total amount of the lactone solvent (b3) with six or more membered rings. A non-aqueous ink composition according to any one of claims 1 to 4.

6. The aforementioned resin includes at least one selected from the group consisting of acrylic resins, vinyl chloride-vinyl acetate copolymer resins, and cellulosic resins. A non-aqueous ink composition according to any one of claims 1 to 5.

7. The content of impurities derived from the lactone solvent (b3) with six or more membered rings is 0.5% by mass or less of the total amount of the lactone solvent (b3) with six or more membered rings. A non-aqueous ink composition according to any one of claims 1 to 6.

8. The lactone-based solvent (b3) with six or more member rings contains ε-caprolactone. A non-aqueous ink composition according to any one of claims 1 to 7.

9. The water content is 1.0% by mass or less of the total amount of the non-aqueous ink composition. A non-aqueous ink composition according to any one of claims 1 to 8.

10. Used in resin substrates A non-aqueous ink composition according to any one of claims 1 to 9.

11. Dispense the non-aqueous ink composition according to any one of claims 1 to 10 onto the surface of a substrate using an inkjet method. Recording method.

12. Dispense the non-aqueous ink composition according to any one of claims 1 to 10 onto the surface of a substrate using an inkjet method. Method for manufacturing records.

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